Vibratory mill drive



June 18, 1963 R. M. CARRIER, JR.. ETAL 3,093,941

VIBRATORY MILL DRIVE 3 Sheets-Sheet 1.

Filed July 2, 1959 5 RR 0 m o bm RS RS W HOU MM M T W EN wwm RJA BY W ATTO NEYS June 18, 1963 R. M. CARRIER, JR., ETAL 3,093,941

VIBRATORY MILL DRIVE Filed July 2, 1959 5 Sheets-Sheet 2 INVENTORS ROBERT M. CARRIER, JR.. JOHN M. MORRIS ALBERT MUSSCHOOT ATTO EYS June 18, 1963 R. M. CARRIER, JR.. ETAL 3,093,941

VIBRATORY MILL DRIVE Filed July 2, 1959 s Sheets-Sheet s INVENTORS JOHN M. MORRIS Y ALBERT MUSSCHOOT ATTORN S ROBERT M. CARRIER, JR.

United States Patent 3,093,941 VIBRATORY MILL DRIVE Robert M. Carrier, Jr., and John M. Morris, Louisville,

and Albert Musschoot, near Louisville, Ky., assignors, by mesne assignments, to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Filed July 2, 1959, Ser. No. 824,574 3 Claims. (Cl. 51-164) This invention relates generally to vibratory tumbling mills and in particular to an improved drive arrangement that provides enhanced operating performance.

Tumbling mills have long been used in certain types of" manufacturing processes where it is desired to clean up the rough edges of stamped or otherwise formed parts or secure additional agitation and relative movement between the abrasive materials and the work pieces and thus accelerate the process. Such orbital vibrations which may be produced by rotating weights carried on highspeed rotating shafts that are coaxial with or parallel to the axle or axis of the container do not always provide W the best vibratory action. In many cases a linear vibration of the tumbling mill container is preferable to the orbital vibratory motion.

The principal object of the invention is to provide a vibratory drive for a vibratory mill in which the drive produces a linear vibration of the container of the mill in a direction transverse to its axis of rotation. Another object of the invention is to provide means in a vibratory mill for simultaneously rotating the mill to provide mixing and agitating of the contents and vibrating the mill along a linear path that is perpendicular to the length of the axis of rotation of the mill.

These and more specific objects and advantages are apparent from the following description of a preferred form of the invention.

According to the invention the improved vibratory mill comprises a resiliently supported frame in which is journaled a rotatable container for the material to be tumbled. A tuned exciter drive. is applied to the frame to linearly vibrate the frame at a substantial amplitude to cause further agitation of the material in the container while other means slowly rotate the container and thus enhance the mixing and vibratory action of the material in the container.

A preferred form of the invention is illustrated in the accompanying drawings.

In the drawings:

FIG. I is a front elevation of the improved vibratory mill showing the means for driving the container and the means for linearly vibrating the container.

FIG. II is an end elevation, with parts broken away, of the equipment as seen from the right side of FIG. 1.

FIG. III is a plan view of the improved apparatus.

FIG. IV is an oblique view of the vibration exciter as seen from the line IV-IV of FIG. 1.

FIG. V is a cross section of the exciter as seen from the line V-V of FIG. IV.

FIG. VI is a schematic diagram illustrating the cooperation of the various elements to secure the enhanced performance of the equipment.

These specific figures and the accompanying description are intended merely to illustrate the invention and not to impose limitations on its scope.

Patented June 18, 1963 "Ice In the improved tumbling mill, as illustrated in the accompanying drawings, a polygonal drum 10 is carried on stub shafts 11 which in turn are journaled in bearings 12 rigidly mounted in a frame 13. The frame 13 comprises a pair of deep-center girders 14 and 15 the ends of which are supported on flexible air bags 16 and 17 which in turn rest on columns 18 located at the four corners of a base 19. The lower portion of base 19 comprises I-beams 20 and 21 connecting the columns 18 and gusset plates 22 bracing the columns against lateral defiection.

The air bags 16 and 17 are similar to air springs employed as automotive suspension systems and in this arrangement constitute resilient means for supporting the frame 13.

The drum 10 is slowly turned in a counterclockwise direction, as seen in FIG. I, by means of a geared motor 25 that includes a pulley 26 that is connected through a belt 27 to a pulley 28 (FIG. II) mounted on one of the stub shafts v11.

Simultaneously with the slow rotation, the drum 10 is vibrated linearly along an inclined path by means of a vibration exciter 30 the frame of which extends from one of the girders 14 across to the other girder 15 in the space above and to one side of the drum 10. The vibration exciter 30, shown in greater detail in FIGS. IV and V, produces linear vibration along an inclined path normal to the axis of the shafts 11 so as to provide a linear vibration of the drum tending to cause material therein to be conveyed counterclockwise within the drum. Thus the conveying motion of the vibration adds to the conveying motion produced by the slow rotation of the drum so that the two effects are additive in mixing the material and the vibration is particularly effective in producing sliding relative movement between the abrasive material and the articles being processed.

The drum or rotating container 10 is preferably constructed of three major sections which are bolted together to form the drum. By unbolting the sections the drum may be disassembled for cleaning or repair. These three sections include, as indicated in FIG. II, a pair of endplates 31 and 32 and a central prismatic section 33. Each of the endplate assemblies 31 or 32 comprises an octagonal plate, having an outline as seen in FIG. I, that carries the plurality of reinforcing ribs 34 extending radially from the stub shaft 11. The stub shaft 11, and the radiating ribs 34 provide a stiff rigid structure as is required to transmit vibratory forces from the shafts 11 into the container itself.

The middle section of the drum, the part 33, comprises an octagonal open-ended shell the marginal areas which are turned radially outwardly to abut the marginal portions of the end sections 31 and 32 to which they are bolted. A plurality of transverse webs 35 serve to stiffen the individual sides of this middle section of the container.

The interior surfaces of the drum or container are preferably lined with neoprene or other resilient material that is inert to the materials used in the polishing or abrasion processes in the mill. An access opening with a cover 40 is provided in one of the sides of the center section 33 of the drum for loading and unloading the drum. The cover 40 is arranged with latching mechanisms so that it can form a water-tight seal to the container.

As was mentioned previously the drum 10 is slowly turned on the stub shafts 11 by a gear reduction motor 25, the shafts 11 turning in bearings 12 mounted on the deepcenter portions of the side girders 14 and 15. The lateral vibration to enhance the polishing or abrading action of the tumbling materials is provided by the linear vibration of an exciter mass 45 that is resiliently mounted within the exciter housing 30. The exciter mass 45 includes a generally box-like frame that carries bearings 46 and 47 in which an exciter shaft 48 is journaled. The exciter shaft 48, which carries eccentric weights 49 and 50, is

driven through pulley 51 and belt 52 from a constant speed drive motor 53 which is preferably mounted on a bracket 54 extending from one of the columns 18. Clear- .ance holes 55 in the end of the housing 30 admit the shaft 48 and allow it to vibrate relative to the housing. The a box-like exciter frame 45 has interior partitions 56 that serve as stiffeners and as means for increasing the weight of the exciter mass.

The exciter housing 30, in which the exciter mass 45 is mounted, is preferably constructed of a pair of channels 57 and 58 havin-g their flanges facing each other and spaced apart by end plates 59 and 60 to forma generally open-sided box. This housing 30 is then attached by meansof side plates 61 and 62 to the girders 14 and 15.

, making up the frame for the mill.

The exciter mass 45 is resiliently connected to the housing 30 by means of a plurality of air bags 65 which may be similar to the air bags 16 and 17 serving as resilient supports for the girders and which preferably are of the same general construction as the air springs used in many heavy motor vehicles. As indicated in FIGS. IV

and V sixteen of these air bags or air springs are employed eight on each side of the box-like exciter mass 45 to con- :nect it to the "adjacent portions of the housing 30. The elasticity or spring rate of the air bags 65 may be varied V by varying the pressure to which they are inflated. Thus the higher the pressure the higher the spring rate.

For economical efficient operation it is desirable that themass of the exciter 45 be approximately of a combined mass of the frame 13 comprising the side girders 14 and and the drum 10 with the parts rigidly mounted thereon. Satisfactory operation may be obtained with this mass ratio ranging between 1 to 1.5 as one extreme .to about 1 to 6 for the other extreme. If the mass ratio 7 to exert the proper force on the frame 13 and this leads to difficulty with the springs 65.

The operating speed at which the shaft 48 is driven may be fixed by employing a constant speed motor and is selected according to the frequency of vibration desired in the tumbling mill. Once this frequency is selected the inflation pressure of the air bags 65- is then varied until the natural frequency of the vibratory system comprising the exciter mass 45 as one element, the mass of the frame 13 and parts carried thereby as the other element, and the air bags as the spring is slightly above a desired operating frequency. When operated in this condition the inertia force of the exciter mass 45plus the force applied by the eccentric weights 49 and 50 is equal to the interia force of the frame 13 and these forces are each equal to the forces transmitted through the air bags 65. In this condition of operation the relative strokesor motions of the massesare generally inversely proportional to the magnitude of the masses so that the exciter member 45 thus vibrates through a stroke from 3 to 4 times the stroke of the frame 13.

'The directions of the vibrations are indicated in FIG.

8 VI. In this figure, as shown, the drum 10 rotates counterclockwise as driven by the motor pulley 26 and belt 27 at the same time that it is vibrated along an inclined path 70 by forces produced by vibration of the exciter frame or exciter mass 45 moving along the same inclined path 70. As was mentioned previously the magnitudes of the strokes are inversely proportional to the masses the desired vibration.

with the magnitude of the motion of the drum 10 in linear vibration being approximately /3 the movement of the exciter mass 45. The tuning of the system and the relatively low rate of the air bags in shear prevent the buildup of any appreciable vibration at right angles to The elasticity of the supporting air bags or springs 16 and 17 is low enough that only minor vibratory forces are transmitted from the frame 13 through the supporting columns 18.

This drive arrangement makes it possible to impose a vigorous linear vibration on the material contained within the drum-10 as such material is being mixed and tumbled by the slow rotation of the drum so that the abrasivematerial is effective on all parts of the article being polished including interior surfaces of such articles. This operation is thus superior to the orbital vibration ordinarily employed with such types of apparatus.

' Various modifications may be made in the details of construction without departing from the scope of the invention.

Having described the invention, we claim:

1. Avibrating'turnbling barrel assembly comprising, in combination, a resiliently mounted frame,. a symmetrically shaped drum journaled on the frame for rotation about an axis, means for rotating the drum, an exciter mass, resilient means mounting said exciter mass on the frame for the transmission of vibratory force along a line 'directedtransversely through the axis of rotation of the drum, and means for vibrating said exciter mass along a path having a major axis along said line to produce a predominantly straight line vibration of said frame and drum.

2. A vibrating tumbling barrel assembly comprising, in'combination, a resiliently mounted frame, a drum journaled on the frame for rotation-about an axis, means for rotating the drum, an exciter mass, resilient means connecting the exciter mass to the frame for transmitting vibratory force along a substantially straight inclined path generally perpendicular to the axis of rotation of the drum, a shaft carrying eccentric weights journaled in the exciter mass and extending parallel to said axis, said exciter mass and said frame cooperating with the resilient means to form a vibratory system having a natural frequency, and means from driving said shaft at a speed generally equal to said natural frequency.

3. A vibrating tumbling barrel assembly comprising, in combination, a resiliently mounted frame, a multisided drum journaled on the frame for rotation about a generally horizontal axis, means for rotating the drum, an exciter mass that is movable along an inclined path generally perpendicular to said axis, a plurality. of pneumatic springs coupling the exciter mass to the frame and resiliently opposing movement of the exciter mass along such path, a shaft carrying eccentric weights journaled in the exciter mass, and means for rotating the shaft at a generally constant speed equal to a desired operating speed, said pneumatic springs being inflated to a pressure such that said springs cooperate with the exciter mass, the frame and the drum'to form a vibratory system that vibrates along said path with a natural frequency near said operating speed.

2,200,724 Robins -1 May 14, 1940 2,469,484 Thiman May 10, 1949 2,702,633 Dekanski Feb. 22, .1955

' 4 FOREIGN PATENTS 811,439 Great Britain Apr. 8, 1959 

1. A VIBRATING TUMBLING BARREL ASSEMBLY COMPRISING, IN COMBINATION, A RESILIENTLY MOUNTED FRAME, A SYMMETRICALLY SHAPED DRUM JOURNALED ON THE FRAME FOR ROTATION ABOUT AN AXIS, MEANS FOR ROTATING THE DRUM, AN EXCITER MASS, RESILIENT MEANS MOUNTING SAID EXCITER MASS ON THE FRAME FOR THE TRANSMISSION OF VIBRATORY FORCE ALONG A LINE DIRECTED TRANSVERSELY THROUGH THE AXIS OF ROTATION OF THE DRUM, AND MEANS FOR VIBRATING SAID EXCITER MASS ALONG A PATH HAVING A MAJOR AXIS ALONG SAID LINE TO PRODUCE A PREDOMINANTLY STRAIGHT LINE VIBRATION OF SAID FRAME AND DRUM. 